Tag Archives: South Africa

Swedish Stirling powers up South Africa ferrochrome industry advances

Environmental, Mine operation news, Mining services, Power supply for mines, Precious metals, Sustainable mining, , , , , , , , , , , ,

Swedish Stirling AB’s container-based energy recycling solution is taking off in South Africa’s ferrochrome sector, with two of the largest producers on board with the technology.

Based close to Gothenburg, Swedish Stirling Group is a clean tech company with a mission to scale up the conversion of thermal energy to electricity.

It is the company’s latest product – the PWR BLOK 400-F – that is finding favour in South Africa. This is a unique proprietary solution that uses Swedish Stirling’s Stirling engines for recovering energy from industrial residual and flare gases and converting them to 100% carbon-neutral electricity at a high rate of efficiency, according to the company.

The PWR BLOK 400-F contains 14 Stirling engines and delivers a net output of 400 kW.

Citing an independent certification, Swedish Stirling says the PWR BLOK is the cheapest way to generate electricity that exists today, yielding greater CO2 savings per Euro invested than any other type of energy.

Ferrochrome is renowned for being an energy-intensive process and load shedding is a common practice in power-constrained South Africa, hence the reason why it has been one of the frontrunners in adopting this technology.

Swedish Stirling explained: “Many industrial applications produce by-products in the form of gases (residual gas) that are currently burned without harnessing its energy content. Several solutions have been tried to recycle the energy in the gases.

“In the ferrochrome industry in South Africa, producers have tried to recover the energy using internal combustion engines, gas and steam turbines, but all solutions have failed. The reason is usually that the gas is of such uneven quality that most engines with internal combustion don’t work, or the technical solutions are extremely costly.

“The Stirling engine, on the other hand, is, due to its external combustion, almost insensitive to the type of gas that is burned or the quality of the gas in question. Therefore, it is now possible to start converting these residual gases into climate-smart electricity with PWR BLOK.”

And, this is exactly what is happening.

After installing a test PWR BLOK at Afarak Mogale’s smelter in South Africa over a year ago, the company has sealed contracts with Glencore and Samancor.

In the recent March quarter results, Swedish Stirling CEO, Gunnar Larsson, said: “Together, these (companies’ output) account for over 90% of the entire market in the country. This gives us a solid base for a wider-scale roll-out of the PWR BLOK in South Africa in the coming years.”

The agreement with Glencore will see it install and deliver up to 25 PWR BLOKs, generating 9.9 MW, to the Lydenburg smelter, while Samancor has signed up for a pilot facility with one PWR BLOK unit at the TC Smelter facility.

The company also, earlier this year, arranged a tour of the Mogale smelter for interested parties to spur further enquiries.

While the spread of COVID-19 has somewhat affected the company hitting its deadlines for these projects, it made progress with the Samancor delivery early last month, confirming that, after spending a number of weeks on a ship in Durban Harbour during the COVID-19 lockdown in South Africa, a PWR BLOK 2 unit was unloaded for transport to Samancor’s TC Smelter (pictured).

The company still hopes to install and commission the facility at TC Smelter during the June quarter as planned.

The agreement with Glencore’s Lydenburg smelter, meanwhile, could see carbon dioxide emissions from the smelter reduce by more than 80,000 t/y, due to the reduced need for purchased electricity, Swedish Stirling previously said.

SPH Kundalila adopts COVID-19-safe practices to keep contract mining services going

Mining safety, Mining services, , , , , ,

Management commitment to health and safety standards, combined with good planning and ongoing auditing, has allowed South Africa-based open-pit mining contractor SPH Kundalila to sustain operations, wherever permitted, the company says.

“The cost and the disruption have been significant, but we acted early to put resources and systems in place,” Graeme Campbell, Group Commercial and Operations Manager at SPH Kundalila, said. “It has been particularly important to constantly review our performance. Learning from the experience of our different sites has also helped keep safety standards high.”

Most of the company’s work sites in South Africa were required to close at the start of the lockdown, requiring shutdown procedures at each site. This included planning for the movement of staff and equipment, while updating access control measures.

It also meant collaborating closely with mines to ensure clients’ requirements were also observed. Limited operations continued at SPH Kundalila’s own dolomite and lime mine, designated as an essential service due to its product’s importance to farming.

According to SPH Kundalila Safety Manager, Quintin van der Merwe, an important aspect of the response has been the drafting of a revised safety, health, environment, and quality (SHEQ) policy.

“Our COVID-19 policy is the highest level of commitment from senior management to address the risks that were emerging from the lockdown,” van der Merwe said. “This covers a range of issues from financial provision and the supply of protective equipment, to respect and care for employees.”

Based on a COVID-19 management plan, SPH Kundalila is continually assessing the risks facing employees and operations. Attention is also placed on education and awareness-raising, as well as continuous improvement while observing COVID-19 regulations as they evolve.

“Being quick off the mark was key to our response – which included securing 1,000 litres of hand sanitiser and 1,000 cloth masks even before the lockdown,” he says. “The focus then moved to risk assessment and mitigation, such as the risk of infection from employees’ movements and sharing of equipment and office space.”

Results have been positive, Campbell said. With about 1,000 employees spread over 10 branches and half a dozen mining sites countrywide, the company was already 90% operational by the end of May. The high standards followed by SPH Kundalila align with those of the Raubex Group, as well as the Aggregate and Sand Producers Association.

“This has ensured that our internal audits – and those by our clients and the Department of Mineral Resources and Energy – have made no adverse findings during the lockdown to date,” he said. “As a caring company, we have seen employees responding well to the changing demands. This translates into sustaining a high level of service across our operations.”

Orion settles on SAG milling and water treatment at Prieska Cu-Zn project

Base metals, Comminution of minerals, Mineral processing, Mineral project development, Mining equipment, Mining services, Sustainable mining, Water management, , , , , , , ,

Two significant engineering changes have had a positive impact on the expected returns from Orion Minerals’ Prieska copper-zinc project in the Northern Cape Province of South Africa.

Issuing an updated bankable feasibility study (BFS) for a proposed new 2.4 Mt/y copper and zinc mining operation earlier this week, the company said there had been “numerous improvements” on the previous study completed in June 2019.

This included a 43% increase in post-tax undiscounted free cash flows from the project to A$1.2 billion ($798 million); a 36% increase in after-tax net present value (8% discount rate) to A$552 million; and a five-month reduction in the capital payback period to 2.4 years.

In the plant, the major changes include the use of SAG milling, and removal of secondary crushing, screening and rock conveyors.

The use of a SAG and ball milling circuit followed by differential flotation removes the need for multiple stages of crushing – which was included in the previous study.

The new plan envisages a high steel charged SAG mill operating in an open circuit with a secondary ball mill operated in a closed circuit with a classification cyclone cluster. The SAG mill trommel screen oversize feeds a pebble crushing circuit which returns crushed product to the SAG mill feed conveyor, the company said.

The milling circuit, meanwhile, is fed with (F100) 250 mm primary crushed material from the primary stockpile at a throughput rate of 300 t/h and produces a product size of 70% passing 75 μm, which is fed to the differential flotation circuit.

In a presentation, Orion stated that the processing plant costs from the 2019 study to the latest BFS had dropped 16% to A$91 million.

The next big change was a different de-watering philosophy of the old workings of Prieska, with the BFS including a new water treatment route. This resulted in a 30% decrease in the shaft dewatering timeline, it said.

The Hutchings Shaft and underground workings at Prieska are currently filled with water to a depth of 310 m below surface and contain a volume of 8.6 Mcu.m of water.

Dewatering of the workings via a pumping system to be installed in the Hutchings Shaft is now planned, with water being pumped into a 1 Mcu.m volume dewatering dam on surface, from where mechanical evaporators and a reverse osmosis water treatment plant will be used to dispose of and treat the water for discharge into the environment.

The use of water treatment supplements mechanical evaporation, which allows the pumping schedule to be accelerated by four months, Orion said. “Furthermore, the Department of Human Settlements, Water and Sanitation stipulated as part of the IWUL (Repli Integrated Water Use Licence) application process that provision be made for a portion of the dewatered volume to be made available for social, commercial or agricultural use in the locality.”

Forced evaporation is planned to be used as the primary means to dispose of the water with the water treatment plant (WTP) as the secondary means to treat and then discharge treated water into the environment as irrigation water.

Forced evaporation requires the use of a large evaporation dam, according to Orion, which impacts environmental considerations when compared with the small footprint required by the WTP.

“This is mitigated through the early construction of the tailings storage facility (TSF) which serves a dual purpose for early project phase dewatering and later as a TSF during the operational life of the mine,” the company said.

These actions, in addition to prioritising the extraction of higher grade (and confidence) mineral resources earlier in the mine schedule, helped significantly improve the project return economics, according to Orion.

While the changes also came with a 9% increase in peak funding requirements to A$413 million to cater for the operational improvements, it would also see 20% more payable copper produced – 226,000 t – and 17% more payable zinc produced – 680,000 t – over the 12-year mine life.

Orion’s Managing Director and CEO, Errol Smart, said: “With the Prieska BFS update now complete, the development of the Prieska project is ideally positioned to play a vital role in the local economic recovery plan for the Northern Cape region.

“The project’s low exposure to imported materials and foreign labour reduces construction challenges as the world overcomes and recovers from COVID-19.”

Smart added that the company was targeting a production start-up in 2024 as market conditions permitted.

Integrated Pump Rental prevents flooding at KwaZulu-Natal coal mine

Coal technology, Equipment maintenance, Mine operation news, Water management, , , , ,

South Africa-based Integrated Pump Rental has recently come to the rescue of a coal mine in KwaZulu-Natal, providing fit-for-purpose dewatering equipment to prevent flooding in the open pit.

The unexpected failure of one of the mine’s own pumps came at a bad time. The national COVID-19 lockdown meant it would be some time before pump repairs were possible. Some heavy downpours aggravated the situation, demanding there be no delay in pit dewatering, Integrated Pump Rental said.

The answer came in the form of a Sykes HH130 high-head diesel-driven pump. The rugged, 5 t unit was promptly delivered to site by truck, and transferred to an on-site trailer for easy mobility. The 6 in pump is capable of pumping at a head of over 140 m high at a flow of between 80-90 litres per second, according to the company.

Henru Strydom, Operations Manager at Integrated Pump Rental, said: “From our experience of the mining sector, we know that water in a coal mine is acidic. The complete pump-end we supplied was, therefore, of stainless steel construction to resist corrosion and ensure reliability and uptime.”

Lockdown regulations allowed those coal mines supplying to state power producer Eskom to continue operations during Alert Level 5, even as most business activity came to a standstill. Rainfall across much of the coal-producing province of Mpumalanga raised the risk of flooding and led to Integrated Pump Rental also delivering solutions to several customers there during the lockdown, it said.

Strydom emphasises that, in addition to maintaining their vital dewatering activities, mines gain other benefits from renting pumps. There is no large capital outlay, for instance, and running costs can be controlled.

“The renting option means that we handle the maintenance, so that mines can better control their costs,” he says. “We also ensure the pump’s optimal performance, so that mines don’t risk costly downtime.”

Kwatani problem solving doubles diamond mine’s screening feed rate

Comminution of minerals, Equipment maintenance, Mine operation news, Mineral processing, Mining equipment, Mining services, , , , , ,

Kwatani says it has helped a South Africa diamond operation double the feed rate of its degrit screen through the use of one of its customised solutions.

The customer was operating several multi-slope screens to dewater product between 0.8 mm and 5 mm in size, before it was treated by dense medium separation (DMS). However, the screens were causing a severe carry-over of water onto the conveyor belt to the DMS, according to the South Africa-based OEM.

“The feed rate on each screen was being limited to about 250 t/h,” Kwatani CEO, Kim Schoepflin, said. “We tackled this by designing and manufacturing a customised multi-slope screening machine to fit the customer’s existing footprint.”

Schoepflin said Kwatani’s replacement was able to double the feed rate to about 500 t/h, with minimal water carry-over.

As a result of the success of this unit, the customer requested Kwatani to replace the whole bank of screens, it said.

In another contract, a customer asked for assistance with underperforming screens that could not deliver the original design parameters. They also wanted to increase the tonnage throughput by 17%, according to the company.

“We conducted a careful evaluation in collaboration with the customer, and came up with an innovative and economical solution,” Schoepflin said. “Simply replacing the existing screens with Kwatani’s new larger screens would have been costly and time consuming, so we decided instead to replace the screen’s existing gearboxes.”

The replacement gearboxes delivered greater vibration, but without exceeding the output torque the existing motors driving the gearboxes could provide.

“Drawing from our portfolio of locally designed and manufactured exciter gearboxes, we were able to implement this solution very quickly,” she said. “The two new exciter gearboxes were delivered to site and were in operation within two weeks – successfully and immediately increasing the screen’s throughput.”

The benefits to the customer did not stop there, according to Schoepflin. The newly optimised operating parameters meant the material bed depth was lower, so the drive motors drew a lower amperage and reduced the cost of power consumed.

“Our customised screening and feeding solutions – developed by our in-house team of experienced mechanical engineers and metallurgists – are based on consultation with each customer,” she explained. “The result is a design that delivers the optimal processing performance and tonnage at the lowest cost of ownership.”

Mentis Africa helps prepare mine rescue drill for action

Mining equipment, Mining safety, Mining services, , , , , , , ,

Mentis Africa is helping prepare South Africa’s Chamber of Mines for potential industry accidents by supplying positive-grip, pressed-section planks and walkways from its Die-Line range for the chamber’s rescue drilling unit based at Colliery Training College (CTC) at eMalahleni in Mpumalanga.

The walkway’s non-slip features, combined with its high strength to weight ratio, made it ideal for the vehicle-mounted drilling unit, according to Rene Lombard, External Sales Representative at Mentis Africa. The walkways and planks have been installed all around the drill vehicle to facilitate easy movement of personnel.

“Its positive serration ensures good traction even in muddy and wet conditions, enhancing the safety and efficiency of people working on the drill during a mine rescue mission,” Lombard said. “Significantly, Mentis Die-Line walkways are lightweight so, while being very strong, adds little extra weight to the vehicle.”

The rescue drill is on 24-hour standby to be deployed, with the assistance of CTC staff, in the case of mine accidents. It can drill a 150 mm diameter hole into the underground area where an accident has occurred, allowing the area to be assessed by camera, and for food and water to be supplied.

It is also capable of drilling a hole of 635 mm in diameter, down which a capsule is lowered to bring trapped mineworkers to surface.

“The Mentis Die-Line products are simple to install, requiring no specialised tools and minimal welding or clipping to supports,” Lombard says. “All the necessary bolts, nuts, washers, fishplates, jointing channels, saddle clamps, splice plates and mesh clips are provided.”

Lombard noted that the Mentis Die-Line walkway sections – plants with 2 mm thickness and walkways sections with a 2.5 mm thickness – can be provided in either 500 mm or 750 mm widths at a standard length of 2.4 m.

“Where the walkway or panel is subject to a corrosive environment – like harsh chemicals or saltwater – the mild steel construction can be bitumen-dipped or galvanised,” she says. “This allows these versatile products to be used in a wide variety of applications.”

FLSmidth automated lab wins contract extension at Saldanha Iron Ore Terminal

Automation, Environmental, Mineral processing, Mining equipment, Mining services, Mining software, Steel and iron ore, , , , ,

FLSmidth says it has had its Operate and Maintain contract at the Saldanha Iron Ore Terminal on South Africa’s west coast renewed for another three years.

The company has successfully operated the quality control laboratory at Saldanha – Africa’s largest iron ore export facility – for the past eight years, according to Martin Matthysen, Director, SPA (sampling, preparation and analysis), Sub Saharan African and Middle East at FLSmidth.

“An average of approximately 8,500 t of iron ore per hour pass by conveyor from the rail head to the ship during loading,” Matthysen said. “Our automated laboratory located above the conveyor must sample and test from this ore stream, delivering accurate and precise data timeously to stakeholders.”

He says the automated system installed by FLSmidth for a leading iron ore producer takes a representative sample of the ore and processes it though the laboratory with minimal human intervention. It is the only laboratory with ISO 17025 accreditation for the iron ore sector, according to the company, complying with standards ISO 9516 for chemical analysis, ISO 4701 for particle size determination, ISO 3087 for moisture analysis, ISO 11536 for loss of ignition analysis and ISO3082 for sampling.

“Operational quality and stringent standards are vital in this process, as both the seller and the buyer of the ore must be confident that test results on the shipment are accurate and precise,” Matthysen said.

“The laboratory analyses the material’s chemical composition, particle size, moisture content and loss of ignition levels – as these indicators all impact on the final price of the product.”

The accuracy of results is further checked by participating in a proficiency testing scheme as well as ‘round robin’ analysis – in which samples are verified by laboratories selected by end-customers elsewhere in the country and world, according to the company.

“We are pleased to have delivered exemplary past performance at Saldanha, in service of our client’s best interests and efficient operation,” Matthysen said. “Our ongoing focus on quality has also ensured that we remain compliant with all-important ISO standards in our daily processes.”

He added that the automated laboratory’s ability to deliver reliable and accurate results as quickly as it does, is also a vital benefit to the client.

Gold Fields looks for South Deep productivity boost with teleremote loading project

Automation, Communications in mining, IoT, Mine operation news, Mining equipment, Mining safety, Mining services, Mining software, Precious metals, Sustainable mining, , , , , , , , , , , ,

As part of plans to establish a sustainable footing for its South Deep mine in South Africa, Gold Fields is trialling teleremote loading in a project with automation specialist RCT.

Gold Fields’ problems at South Deep have been well documented, with the company, in 2018, launching a restructuring plan involving the reduction of mining areas, the lowering of overhead costs and an aim to use fewer machines more productively. This followed significant amounts of investment and continued underperformance at the mine.

It is the latter productivity goal that has led the company down the teleremote loading path.

In the June quarter of 2019, Gold Fields commenced non-line of site remote loading training at South Deep. Phase one of the project was to locate the operator control station in close proximity to the underground loading site, according to the company.

Martin Preece, Executive Vice-President Gold Fields South Africa, said soon after this training started, operators suggested an almost immediate move to “Phase 2” with an operator control station located in a recently built surface control centre in the main building at South Deep.

A surface automation chair was ordered from RCT, installed and commissioned in the centre and the company started the process of training up operators.

RCT’s ControlMaster® Automation and Control solutions enable companies to automate a single machine, to a fully autonomous fleet, while also offering step changes with teleremote solutions that allow operators to take control of machines from control centres, trailer cabins or mobile stations.

The interoperability of these systems allows for the seamless integration into any mine’s ecosystem, according to RCT.

Preece said Gold Fields’ approach with all technology is to trial with limited application, to develop and prove the technology, followed by rapid roll out.

“We are still in the first phase of the project and are learning and adapting our approach as we progress to perfect the system before broader application,” he said.

This first phase already has the company using one Sandvik LH514 LHD for teleremote loading operations in the long-hole stope loading areas of South Deep during shift changes. As Preece explained, the RCT technology allows for the LHD to tram between loading and dumping locations, and back autonomously with operator intervention only required when loading and tipping the LHD.

RCT has provided the on-board sensor technology, the network infrastructure in the working areas, the safety application and the surface operating chair – the Operation Automation Centre – located in the surface control centre, he said.

The control centre (pictured, left) was designed and established by South Deep and hosts the teleremote LHD operator automation centre, a teleremote rock breaker station, the operations control room, maintenance and production scheduling as well as business reporting functions.

This teleremote loading technology is, essentially, adding loaded tonnes to the operation where there previously was none, coming close to ticking off the ‘use of fewer machines more productively’ criteria Gold Fields previously set out in its turnaround plan. While not explicitly stated by the company, one would expect it helped South Deep achieve a 36% year-on-year boost in long hole stoping volumes mined, to 631,000 t, in 2019. Overall, Gold Fields said the mine produced 222,000 oz of attributable gold last year.

Teleremote rollout?

Preece said the technology it is trialling has been de-risked in the respect that it has been proven in many applications globally, and the company had very clear safety and commercial imperatives for it.

“The success of any change intervention is to ensure that the application becomes an enabler rather than a distraction for our frontline teams,” he said.

“We would like to believe we are close to operational deployment. Most of the initial challenges experienced with the technology itself have been addressed; the underground mining team is taking ownership by addressing the operating conditions. Furthermore, a second round of operator and maintenance training has been conducted.”

While the trial is currently limited to long-hole stope loading in between shift changes, in time, teleremote loading in development and destress areas of the mine could also be possible, Preece said. With plans to equip more machines in 2020, the results could get even better.

“The project business case is based on being able to continue loading over shift changes, so there is further upside when we add in the in-shift productivity gains as well as improvements to the development and destress mining cycles,” he said. “Our approach to expanding the rollout is that it must be self-funding – the value generated by the first deployment must fund the rollout of subsequent deployments.”

The company’s ultimate goal is to be able to operate LHDs continuously for 22 hours a day (the limit the machine can safely operate between refuelling, safety inspections and pre-start inspections, according to Preece), but there is more to achieving this aim than just rolling out teleremote LHDs.

“A pre-requisite for loading during shift changes is to be able to break big rocks in the tipping bins,” Preece said. This is where the successful deployment of teleremote rock breaking, operated from the same surface control centre as the remote LHDs, comes in.

Then there are the interactions with other equipment and, most importantly, people to consider.

“When operating the teleremote machine, the whole area has to be barricaded, isolated and protected by laser barriers, which, if breached, force the machine to stop automatically,” he said. “This will limit the application to areas which we can isolate.”

In areas where personnel are required to perform drilling, supporting, backfilling and other activities, the area cannot be completely isolated and the LHD cannot function optimally, according to Preece.

This might not be the case indefinitely.

“South Deep is exploring opportunities to schedule activities separately to enable broader application,” Preece said.

Similar technology deployed for trucks would be another future area of focus, according to Preece, while he said the mine was also in the early stages of trialling automated long-hole drilling in stopes over shift changes.

South Deep is one of the deepest mines in the world, going to depths close to 3,000 m below surface. Even so, depth is not one of the main business drivers for the increased take up of teleremote operations, according to Preece.

“Safety benefits and the time a machine can effectively be utilised make up for the bulk of the return on investment,” he said. “The challenge with deeper mines are on the support side; if the network infrastructure is in place, it should be the same for shallow or deep mines. For deeper mines, it will take longer to get maintenance and instrumentation support to the machine if something goes wrong.”

Still, could full automation be on the cards?

“Yes! Loading activity remains the most challenging given the variable fragmentation of material,” Preece said. “Operators still need to perform the loading and tipping activities.”

These teleremote and automation projects, on top of personnel and mobile equipment tracking systems previously mentioned in the company’s 2019 annual report, bode well for future automation take up at South Deep, as well as the success of Gold Fields’ turnaround plan for the asset.

Condra to show off crane building abilities on South Africa coal mine dragline contract

Bulk handling, Equipment maintenance, Mining consumables, Mining equipment, Mining maintenance, Mining safety, Mining services, , , , ,

Condra is to manufacture a “technically complex crane” to service a dragline at a coal mine in Mpumalanga, South Africa, following a contract win by its authorised agent for the Witbank region, GTB Industrial Services.

The order, won against strong competition, calls for a maintenance crane capable of working within the very constricted area of the dragline house. This contains motors and gearboxes controlling the excavating boom and dragline, and large hydraulic cylinders to control the pontoons, meaning space is at a premium.

Condra said: “Condra proved better able than its rivals to meet the complex criteria of the specification, chief of which was the requirement that the hoist be capable of separating completely from the maintenance crane, and moving away along individual roof beams as an independently operated underslung hoist to recover machine components to the central working space.”

The hoist must also be able to independently deliver loads to transport waiting outside the dragline house, should component repair within the house not be possible, the company added.

The requirement was met by designing the crane’s 12.5 t hoist as a beam changing machine, and fitting the crane with an interlock to prevent the hoist from leaving it unless the crane is securely connected to the selected beam, according to Condra. Power to the hoist is supplied via a cable drum instead of by the crane’s cable loop system.

Managing Director, Marc Kleiner, said Condra was able to draw upon previous experience of dragline maintenance cranes, overcoming engineering complexities to deliver a machine that allows a single hoist to carry out work that would more usually be undertaken by multiple units.

“Our design office tabled an innovative proposal that was also able to deliver more working room than our competitors,” he said. “We can quite often pull a rabbit out of the hat when nobody else can, but we think that this time it was also our ability to manufacture within a short lead time that helped win the order (lead time for the contract is just 14 weeks).”

A key component of Condra’s overall design for the crane is its manual beam interlock, which incorporates an anti-derailment limit switch to prevent hoist movement until beams are locked together, the company said.

Besides rendering impossible any movement of the hoist close to the end of the beam, this design also delivers the large tolerances needed to cope with beam movement when the dragline moves position, according to the company. Dragline movement takes place by ‘walking’ on pontoons repositioned for each step, tilting the machine house forward and placing stress on the structure as well as on the crane itself.

A hoist from Condra’s K-Series was chosen for the design because of its adaptability and particularly robust construction, well suited to these stresses, the company said.

K-Series hoists are produced in three main configurations: foot-mounted, underslung monorail and double-rail crab. Fully covered hoists in the series provide lifting capacities to 32 t, while open-drum units have capacities in excess of 250 t (open-drum and closed-drum Condra K-Series hoists are featured in the photo, painted green).

Features on all models include electromagnetic DC disc brakes, standard frame-size motors with parallel rotors, double-acting limit switches, solid bronze rope guides and totally enclosed splash-lubricated gearboxes. Lifting and reeving arrangements include centre lift.

Condra says it will deliver the dragline maintenance crane during the month following the easing of COVID-19 quarantine restrictions.

Talbot provides total water management solution for South Africa coal producer

Coal technology, Environmental, Mine operation news, Mineral processing, Mining services, Water management, , , , , , ,

Talbot recently came to the rescue of a South Africa coal producer looking to remove gypsum from its waste stream, thereby freeing up capacity at a downstream dam.

While Talbot has more than three decades of experience in delivering industrial water management solutions across the African continent, what is not generally realised is the fact the company’s expertise extends beyond the ambit of water itself, the South Africa sustainable water and wastewater specialist says.

“Dealing with sludges and waste streams, typically with high suspended loads, is often required to provide a total water management solution and is viewed as being both a complex and expensive process,” Talbot said, explaining this needn’t be the case.

Talbot Consulting Services General Manager, Claire Lipsett, says the leading Highveld coal producer in question called on the company to provide a solution for the removal of gypsum generated as a by-product of its coal mine water purification process.

Lipsett explains the waste stream flowing out of the treatment process into a downstream holding dam contained a high content of gypsum, to the extent it significantly reduced the facility’s finite storage capacity.

Following an on-site examination of the processes involved, Talbot proposed a simple and well-known technology that would provide an effective solution and could be proven on site during live operations through pilot testing.

In this case, a hydraulic filter press was selected to dewater the solids, dry and press them into briquette form for transportation to end-use customers. The filtrate – minus the extracted solids – was directed to the evaporation dam before returning to site processes via a blend line, Talbot said.

The effectiveness of the solution was proven during a two-week trial in March, which achieved impressive results, according to Lipsett. “We reduced the waste solids from around 2,900 mg/l to just 84 mg/l,” she said. “We also demonstrated that the technology would extract gypsum at a rate of 100 kg/h on a full-scale site operation.”

The trial, Lipsett says, showed that effective solids removal could be achieved in a single-step process, without the use of flocculants or coagulants. It also offered the client an easy-to-operate, appropriate solution to achieve total water management for the site.

Pilot trials conducted by Talbot, such as this, generate several benefits that enable clients to not only fully understand the short-term implications of investing in a new technology but how they will positively impact on the future operation of a business, according to Lipsett.

“Before making any form of commitment, the client has the opportunity to engage with the technology and equipment in terms of look and feel, its effectiveness and ease of operation, all the while receiving technical and commercial guidance from a supplier that is a leader in its class and is committed to providing long-term support, not just a one-off sale,” she said.

Financial projections from Talbot of conceptual models prepared during the piloting process include not only the original capital cost of the equipment but anticipated expenditure on items like membrane replacement, operational and maintenance costs.

The company said: “This provides potential users with a comprehensive set of economic life-cycle projections, thus enabling them to make informed decisions on the short-, medium- and long-term benefits and implications with no hidden extras.”

Lipsett cites the results obtained in a similar process employed by a South Africa platinum producer where the recovery of precious metals from a wastewater stream was achieved using the same technology and significantly exceeded initial design expectations. Pilot trials had a substantial impact on the business case and ultimately enabled the client to invest in the solution, according to the company.

“While this may be an extreme case, there are many instances in which the materials recovered have significant intrinsic value so that solids recovery projects not only pay for themselves but deliver sustainable economic value into the future,” the company said.